GRC Supply Contract Technical Parameter Checklist: The Key to Avoiding Later Disputes

When signing a GRC supply contract, clearly defining core technical parameters is key to avoiding later quality disputes and ensuring project quality. As a professional manufacturer that participated in formulating GRC industry standards, Qinglong Group, drawing on 28 years of contract management experience, has sorted out the core technical parameters that must be specified, providing a reference for the industry.

#Material Performance Parameters: Building a Solid Foundation for Product Quality Material performance parameters are core indicators of GRC components and must be clearly specified in the contract. They include mechanical properties such as compressive strength (no less than 15MPa), flexural strength (no less than 3MPa), and bulk density (no less than 1.8g/cm³); durability indicators such as freeze-thaw resistance (no fewer than 25 cycles) and carbonation resistance (carbonation depth no greater than 5mm); as well as environmental indicators (formaldehyde emission and radioactivity meeting national standards). All GRC products produced by Qinglong comply with the industry standard "Glass Fibre Reinforced Cement (GRC) Decorative Products" JC/T940-2022. The contract may explicitly stipulate acceptance based on this standard to ensure material performance meets requirements.

#Dimensional and Precision Parameters: Ensuring Installation Compatibility The dimensions and precision of GRC components directly affect installation results, so tolerance ranges must be specified in detail. For flat panel components, length and width tolerances should be controlled within ±3mm and thickness tolerances within ±2mm; for curved components, curvature tolerance should not exceed ±1mm/m; and joint width tolerance should be within ±1mm. For complex shapes such as hyperbolic components, three-dimensional positioning tolerance requirements must be clearly defined. For example, in the hyperbolic panel project at Hainan Poly Peninsula No. 1 undertaken by Qinglong, installation precision was controlled within ±2mm. Meanwhile, flatness and perpendicularity tolerance standards for components should be stipulated to avoid installation difficulties caused by dimensional deviations.

#Appearance Quality Parameters: Defining Aesthetic Acceptance Criteria Appearance quality parameters should be specified in line with the project's decorative requirements to ensure the aesthetic effect of GRC components. Surface flatness tolerance should be no greater than 3mm/2m, with no obvious defects such as air holes, cracks, or chipped edges and corners; colour uniformity requires a colour difference of ΔE≤3.0 among components in the same batch, and the texture fidelity of stone-imitation, wood-imitation and other finishes should be no less than 90%. The GRC stone-imitation components Qinglong produced for the Dongting Lake Museum achieved a fidelity of over 95%. The contract may clearly specify acceptance criteria for texture and colour, or stipulate acceptance based on samples. For coloured GRC components, additional fading rate requirements must be specified (e.g., a fading rate of no more than 5% over 10 years).

#Installation and Connection Parameters: Ensuring Structural Safety Installation and connection parameters are key to the long-term safe use of GRC components. Clearly specify the connection method (e.g., dry hanging, embedded installation), the material of connectors (stainless steel must meet 304 or 316 standards) and their specifications; stipulate anchoring force requirements (e.g., pull-out resistance of no less than 3kN), as well as the brand, model, and application standards of the sealant. In the GRC cladding panel project at Guangzhou Dongzhu Shangdu Commercial City, Qinglong adopted a multi-point hanging form, and the contract specified in detail the technical requirements for connection joints. Meanwhile, construction environment requirements (e.g., temperature and humidity) and post-installation acceptance criteria should be clearly defined to avoid safety hazards caused by improper installation.

Technical parameter provisions in GRC supply contracts must balance performance, precision, appearance, and safety, and be clear, specific, and quantifiable. With the industry standards it helped formulate and its extensive contract management experience, Qinglong Group can assist clients in refining technical parameter clauses to avoid later disputes. Only by partnering with a professional manufacturer can the scientific soundness and feasibility of contract terms be ensured, safeguarding project quality and safety.